Straightening machine for pipe-like articles

ABSTRACT

For straightening pipes, there is provided a machine with input and output rollers between which are rotatably and coaxially arranged three casings internally carrying tongue passes which engage and straighten the pipes. The casings are driven in opposite directions.

United States Patent Popov et al.

[ 51 3,672,197 [451 June 27, 1972 [56] References Cited UNITED STATES PATENTS 518,403 4/1894 Haas ..72/164 X 1,936,679 11/1933 Leech ..72/79 3,068,931 12/1962 C1ever.... .....72/164 X 3,222,906 12/ 1965 Auvin ..72/164 X 760,406 5/1904 Gregersen ..72/99 1,538,325 5/1925 Higgins ....72/79 2,779,384 /1957 Knauth et a1. ..72/99 Primary Examiner-Milton S. Mehr Attorney-Waters, Roditi, Schwartz and Nissen [5 7] ABSTRACT For straightening pipes, there is provided a machine with input and output rollers between which are rotatably and coaxially arranged three casings internally carrying tongue passes which engage and straighten the pipes. The casings are driven in opposite directions.

2 Claims, 2 Drawing Figures 3 1 0 FA 4 s a A n e e m 0::

i (I 3 f 9 o :1: a E, o I ll 3 I 1 m V PATENTED Jun 2 7 1972 SHEET 10F 2 STRAIGHTENING MACHINE FOR PIPE-LIKE ARTICLEQ The present invention relates to machines for straightening elongated articles, such as, for example pipes, bars or rods, and, more particularly, continuously moving thin-walled pipes with a ratio of inside diameter to wall thickness above lOO.

Known in the art are pipe-straightening machines comprising input and output pulling rolls and straightening rolls located between the pulling rolls and forming a so-called tongue pass" mounted in a single rotating drum.

A disadvantage of the known machines is that a high torque is applied to the pipe being straightened while the drum and the straightening rolls rotate in one and the same direction. To keep the pipe from rotating it has to be clamped in the input rolls with a great force which may lead to residual defonnations of the pipe wall. Moreover, since the straightening rolls are connected directly with the drum, the bending of the pipe required for straightening is achieved by moving and loading only one roll, which fails to insure the required uniform distribution of load among all the rolls of the tongue pass.

An object of the invention resides in eliminating the aforesaid disadvantages and in providing a machine for quality straightening of thin-walled pipes without residual deform tion of-the pipe material.

The above and other objects are achieved by providinga pipe straightening machine whose straightening unit ensures uniform distribution of the force applied to the straightening rolls and. prevent twisting of the pipe in the process of straightening.

This is achieved, according to the invention, by mounting tongue passes with straightening rolls in at least three separate casings installed one after another along the axis of pipe feed with a provision for rotation and connected with individual drives which rotate the adjacent casings in opposite directions.

It is practicable to rigidly connect the straightening rolls of the tongue pass in each individual casing by a ring installed inside the casing with a provision for adjusting it in the direction perpendicular to the axis of rotation of the casings.

Such an arrangement allows the machine to straighten thin walled pipes (with a diameter-to-wall thickness ratio of 200-300 and above) of unlimited length. Apart from eliminating the curvature of the pipes, the machine is capable of calibrating their profile and making good shallow dents.

The invention will next be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view which illustrates the pipe straightening machine according to the invention; and

FIG. 2 is a sectional view along line A-A in FIG. 1.

The pipe straightening machine comprises three casings 1 (FIGS. 1 and 2) installed one after another along the axis of the pipe feed.

Each casing is mounted on rolling contact bearings 3 installed inside and outside the casings and has an individual drive consisting of, for example, a V-belt drive 4. The adjacent casings 1 rotate in opposite directions.

Inside each casing 1 there is the so-called tongue pass" consisting of a number of straightening rolls 5 mounted on the ends of guide bushings 6 rigidly interconnected by an inner ring 7. The position of the ring 7 with respect to the center of rotation of the casing 1 can be adjusted by means of a screw 8 which moves the ring 7 along guide pins 9. The ring 7 is sub- 5 jected to the heaviest loads and its position is responsible for the quality of straightening.

The machine has rolls 10 at the input and output ends, said rolls feeding thin-walled pipes with a relatively large initial curvature into the straightening rolls 5 which are skewed relative to the pipes which they peripherally engage. As the casing l and the tongue passes rotate in opposite directions, the pipe 2 moves forward only under a minimum clamping pressure of the feed rolls 10 which improves the quality of straightening and eliminates residual twisting defonnations.

When it becomes necessary to straighten pipes of a different diameter, each straightening roll 5 has to be adjusted for radial and angular position. The bending of the pipes required for their straightening is achieved by moving the ring 7 laterally together with the rolls 5 of the middle tongue pass in relation to the center of rotation of the casings 1. This allows the machine to be used for straightening pipes with extrathin walls and insures a uniform distribution of forces among all the rolls 5 of the tongue pass.

The pipe 2 is fed for straightening to the feed rolls 10 which pull it through the tongue passes of the casings l.

The straightening rolls 5 of the adjacent casings, fitting uniformly around the pipe 2 with a light interference, rotate in opposite directions, insuring the centering of the sections of the pipe 2 and straightening of the bent sections without residual twisting deformations of pipes even with extra-thin walls, since the existing minimum twisting stresses are made up for in the machine. Because all the rolls of the tongue pass take part in straightening the curvature of the pipe, the wear of the rolls is reduced and the life of the machine is extended.

We claim:

l. A machine for straightening continuously moving elongated pipe-like articles, said machine comprising: input and output means for feeding a pipe in longitudinal direction; at least three separate casings rotatably arranged in sequence along the axis of the pipe between said input and output means; tongue pass means including straightening rolls skewed with respect to and peripherally engaging the pipe to straighten the same, said tongue pass means being mounted in and rotatable with said casings, each tongue pass means including a ring installed inside a corresponding casing, the straightening rolls of each tongue pass means being rididly interconnected by the corresponding ring; means for adjustment of said rings perpendicular to said axis; and individual drive means for rotafing adjacent of said casings in opposite directions around said axis.

2. A machine as claimed in claim 1, wherein the casings are of equal diameter and are concentric, said machine further comprising means supporting the casings for individual rotation and means between the casings to space the same and permit rotation therebetween. 

1. A machine for straightening continuously moving elongated pipe-like articles, said machine comprising: input and output means for feeding a pipe in longitudinal direction; at least three separate casings rotatably arranged in sequence along the axis of the pipe between said input and output means; tongue pass means including straightening rolls skewed with respect to and peripherally engaging the pipe to straighten the same, said tongue pass means being mounted in and rotatable with said casings, each tongue pass means including a ring installed inside a corresponding casing, the straightening rolls of each tongue pass means being rididly interconnected by the corresponding ring; means for adjustment of said rings perpendicular to said axis; and individual drive means for rotating adjacent of said casings in opposite directions around said axis.
 2. A machine as claimed in claim 1, wherein the casings are of equal diameter and are concentric, said machine further comprising means supporting the casings for individual rotation and means between the casings to space the same and permit rotation therebetween. 